Conventional firefighting techniques usually involve aiming a large volume of water at a central point in a fire in an attempt to cool the combustion below the flash point of the incendiary material. It has been found that depriving a fire of oxygen is often a more effective method of controlling a blaze. Nozzles that can produce a dense fog have been found effective in dealing with fires in this fashion. The most effective type of fogging nozzle is one that can produce a fog without any holes or pockets of air within it. Nozzles that can produce such a dense and uniform fog or mist are also useful for quenching and tempering metal and for applying paint and other finishes. The following are some examples of fogging and misting devices that have been developed.
U.S. Pat. No. 5,253,716, issued to Mitchell, is directed to a fog producing firefighting tool has a nozzle which includes a plurality of apertures oriented so that when pressurized fluid flows through each aperture, the liquid impacts at an angle of 90 degrees with another stream of liquid to atomize the liquid and create a fog. The firefighting tool is of modular construction which includes a first member, one or more intermediate members, and an end member wherein the members are connected to each other by means of quick coupler devices which can be readily locked into coupled relationship and will not interfere with the usage of the tool when it is forced into or removed from a hole in a structure.
U.S. Pat. No. 2,235,258, issued to Jones is directed to a fire extinguishing nozzle. The nozzle head includes a central pair of relatively large orifices and two pairs of relatively small orifices positioned at the sides of the central pair. Each pair is so arranged that the ejected streams of water leaving the nozzle head from each individual pair of orifices are caused to impinge together in such a way that the resulting impingement will cause the two streams of water to be broken up into a spray in which substantially all of the particles of the water are of substantially uniform size.
U.S. Pat. No. 6,398,136, issued to Smith discloses a fire-fighting tool incorporates a twist-lock mechanism whereby various nozzles can be interchanged for particular fire-fighting purposes. Included in such nozzles are a penetrating nozzle having a doubly beveled front end for easier access through a roof, and various fluid ejection and misting elements that can be configured in terms of fluid aperture angles to produce a mist directed somewhat back towards the user, transverse to the nozzle, or forward from the nozzle. A non-penetrating embodiment of the invention also uses an end ejecting misting region. The foregoing elements can be used in conjunction with various extension wands, which are removably connectable fluid channels bent to various angles, so as to provide easier access to fires that are located within recesses of buildings, motor vehicles, or boats and the like.
U.S. Pat. No. 5,520,331, issued to Wolfe describes a convergent/divergent gas nozzle atomizes a liquid provided through a lid delivery tube having an aperture which is centered within a central gas conduit of an upstream mixing block connected to the nozzle. The aperture of the liquid delivery tube is located just upstream of a narrowed throat of the nozzle. The throat of the nozzle is dimensioned such that its inside diameter is equal to the outside diameter of the liquid injector tube. A spout is located at the discharge end of the nozzle which has an inside diameter equal to two times the inside diameter of the throat. This nozzle displays superior performance, providing an extremely fine mist having high momentum. This nozzle is particularly well-suited to fire extinguishment.
U.S. Pat. No. 5,553,784, issued to Theurer is directed to a nozzle assembly provides a high pressure dispersion of water particles in a misting process. The nozzle includes multiple arrayed discharge outlets into a single mixing zone wherein the discharge outlets are concentrically arranged alternating between water and gas streams. The mist from the novel arrangement is highly dispersed, providing excellent gas cooling operation with minimal maintenance.
It is an objective of the present invention to provide a misting or fogging device capable of a dense and uniform mist. It is a further objective to such a device be compatible with existing fire sprinkler systems in terms of required pressure and fire sensing activators. It is yet a further objective of the invention to provide a device suitable for point dispersion and another device capable of lateral dispersion. It is still a further objective to provide devices suitable for metal quenching and for surface finishing such as painting. Finally, it is an objective to provide a misting or fogging device that is simple and inexpensive to produce while fulfilling all of the described performance criteria.
While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified.